Help with Casio keyboard not working

[73's de Edd]

FIO . . . .
assuming pin #1 is the one closest to the power plug
Viewing the CA5668 with its labeled side being readable, there is a divot within the case just above the units assigned pin # 1.

Now, back to your situation of having your current metering knob setting to a lower ma range.
No damage was inflicted o your meter, due to your having a low resistance of the meters very low resistance 10A current shunt in circuit, because you had already plugged into the 10 A receptacle.

With your metering info, it is suggestive of the voltage regulator working if you earlier read ~11.54 Vdc at the power input connecto and then being on down to ~9VDC at the pin 11 power input of the LA4127 audio power output IC.

Seemingly the audio output IC is not wanting to pull and consume any power . . .OR . . . your reading of the instant current capabiliy of the AC adapter is actually being correct.. . . . adapter isht KAPUT ?

Seems logical to prove that now:
First, find your . . .perceived . . . freshest / "hottest " of your AAA thru D dry cell cell options and plug in meter leads for 10A DC current range and set selector knob to 10 A this time.
Then do that lightning quick test of your selected cell . . . or, sequentially, test multiple cells . . . now, a HOT cell will read from 5-6 amps just for that instant test.
As for finding a cell testing at 1 amp . . . shucks,I wouldn't even use that one in a battery powered clock.
The point is now, that if you can find cells testing up to that HOT current capability in cells being tested, your meter being used in 10 amps testing, is OK.
So that AC adapter is not putting out anywhere near the power being needed.
For even further testing, round up 6 hot cells to totally power up the unit with batteries and that should let us then see if the LA4127 is operative or not.

 

[LJ89]

FIO . . . .
assuming pin #1 is the one closest to the power plug
Viewing the CA5668 with its labeled side being readable, there is a divot within the case just above the units assigned pin # 1.

Now, back to your situation of having your current metering knob setting to a lower ma range.
No damage was inflicted o your meter, due to your having a low resistance of the meters very low resistance 10A current shunt in circuit, because you had already plugged into the 10 A receptacle.

With your metering info, it is suggestive of the voltage regulator working if you earlier read ~11.54 Vdc at the power input connecto and then being on down to ~9VDC at the pin 11 power input of the LA4127 audio power output IC.

Seemingly the audio output IC is not wanting to pull and consume any power . . .OR . . . your reading of the instant current capabiliy of the AC adapter is actually being correct.. . . . adapter isht KAPUT ?

Seems logical to prove that now:
First, find your . . .perceived . . . freshest / "hottest " of your AAA thru D dry cell cell options and plug in meter leads for 10A DC current range and set selector knob to 10 A this time.
Then do that lightning quick test of your selected cell . . . or, sequentially, test multiple cells . . . now, a HOT cell will read from 5-6 amps just for that instant test.
As for finding a cell testing at 1 amp . . . shucks,I wouldn't even use that one in a battery powered clock.
The point is now, that if you can find cells testing up to that HOT current capability in cells being tested, your meter being used in 10 amps testing, is OK.
So that AC adapter is not putting out anywhere near the power being needed.
For even further testing, round up 6 hot cells to totally power up the unit with batteries and that should let us then see if the LA4127 is operative or not.

Ok, So I found 4 x D batteries which were reading ~ 7 Amps, and I found 2 x C batteries which were reading ~ 6 Amps. I put these batteries in the unit, but as there was a little bit of a gap between the + and - terminals of the battery tray, I just stretched out the spring of the negative terminal so that it made contact with the battery. So now all the batteries were in series. The power light came on, but still no sounds when I pressed the keyboard keys.

 

[davenn]

Ok, So I found 4 x D batteries which were reading ~ 7 Amps, and I found 2 x C batteries which were reading ~ 6 Amps.

this doesnt even begin to make sense
You should be measuring voltage across the full set of batteries to make sure it reads the 9 - 10V required

 

[73's de Edd]

GOOD SHOW ! on the "marriage" of those two mechanically dissimilar sized cell famalies.
The series arranged 9 volts battery set times 6 amps equals 54 watts of instant power burst capabilities.
NOW . . . since you got no sound with power up, with volume at max and a keyboard press for commanding of a tone.
We now need to see if that voltage level / presence is MAKING it on over to that LA4127's power input pin of #11.
Can you repeat that test again, with us now using the battery power.
If that somewhat same voltage level is being present, then we need to see if thereactually is any "pressed key tone" getting to the audio input pins
. . . . .#15 and ? (6) . . . . . of that IC. You can see that data sheet totally omitted the other channels input pin number, but by layout symmetry of the audio output pins of #12 and #9, I am highly suspecting that other mystery input pin is going to be #6.
Soooooo . . .now you want to place your metering in AC voltage mode ( to be ranged for 1VAC or less ) and move that RED lead that WAS plugged into 10A socket, back to its normal voltage plug in position.
Then the use of the same meter black ground lead to pin 5 and the red AC meter lead needs to sample both the pin 15 and 6 tmusic tone inputs of that IC after you have powered up and had mamacita press a key for you.
I might expect an incoming tone level to be on down in the two tenths of a volt level . . .or possibly even weaker / lower . until the key is released.
(Pray for an indication / presence ! )
S o o o o . . .if having our chips full power supply level being present, and your actually measuring a generated musical tone coming over to the inputs, and you then measuring its presnce, is leaning towards the LA4127 being suspect.

73's de Edd . . . . .

 

[73's de Edd]

this doesnt(sic) even begin to make sense.

To some, not fully in the know . . . it might not . .
The SITUATION is that he ONLY has a potential rag tag, potpourri of questionable cells in the house on a very early SUNDAY mornings wee hours.
That DYNAMIC INSTANT CURRENT CAPABILITY testing procedure pinpoints your superior cells from any stragglers / duds in the instant peak power capability selection apects.
Luckily, of those that he had to work with, he was able to find inter mate matching , almost as good as 6 new cells, fresh off the store shelf .

Little Johnny Fixerfaster . . .. . .

Being all of 10 years of age, he had been electrically experimenting and found that a copper penny and a zinc penny being separated with a paper blotter soaked in salty water and with attached outcoming wire leads connecting to each of the pennies, would then give a 1.45Vdc reading on his meter. WOW ! 1.45Vdc
So, he had remembered reading of tieing multiple cells together in series and he continues making cells and adding on and testing . Then there is that progress in time when he finally sees a reading of 13.05 VDC . . . .EUREKA !!! . . . . .13.05 VDC . . . . .thats now being enough voltage to jump start a HARLEY.
Which relates to dear ole dad and HIS Harley parked in a corner of the garage with its badly sulphated battery having been pulled and banging around in the bed of his pick-up-an-up truck, until he finally could come up with the required money.
I am sure that you can now visualize his scooping up his PYREX bowl creation and slamming the screen door in his rushing out to the garage to the dangling battery leads of the Harley.
All the while he is thinking 13.05 VDC . . . .13.05 VDC . . .13.05 VDC . . . O O O O H BABYCAKES !
Alas, it was not to be !
Seems like when dad came home and heard of the dejected situation , he just had to explain . . . . INSTANT PEAK CURRENT CAPABILITY . . . by relating to the large SUN Battery charger and Analyzer that Joe Mechanic used down at his garage. He remembered its GIANT voltmeter that read out DC volts and the large knife switch that he would pull down to then see a cherry red glow come from the top of the giant metal box / case. The voltmeter then changed to a lower reading.
And that's the way it was . . . . 70 years ago.

 

[LJ89]

this doesnt even begin to make sense
You should be measuring voltage across the full set of batteries to make sure it reads the 9 - 10V required

Ok will do. I lined up the 6 batteries and I measured 9.32 Vdc

 

[LJ89]

These measurements indicate that power supply is bad. Pin 7 is the power supply input to the regulator and should not be at 0 V. Provided your measurements are correct.

I re tested pin 7 vs pin 4 : 0 V
and pin 7 vs pin 9 : 0.1 mV

but when I test pin 7 against pin 1, or pin 2, they read 9 Vdc.

This might seem like a dumb question but If I use a jumper wire and give pin #7, 9 Vdc could that be a way I can test the chip?

thanks for all the help

 

[LJ89]

GOOD SHOW ! on the "marriage" of those two mechanically dissimilar sized cell famalies.
The series arranged 9 volts battery set times 6 amps equals 54 watts of instant power burst capabilities.
NOW . . . since you got no sound with power up, with volume at max and a keyboard press for commanding of a tone.
We now need to see if that voltage level / presence is MAKING it on over to that LA4127's power input pin of #11.
Can you repeat that test again, with us now using the battery power.
If that somewhat same voltage level is being present, then we need to see if thereactually is any "pressed key tone" getting to the audio input pins
. . . . .#15 and ? (6) . . . . . of that IC. You can see that data sheet totally omitted the other channels input pin number, but by layout symmetry of the audio output pins of #12 and #9, I am highly suspecting that other mystery input pin is going to be #6.
Soooooo . . .now you want to place your metering in AC voltage mode ( to be ranged for 1VAC or less ) and move that RED lead that WAS plugged into 10A socket, back to its normal voltage plug in position.
Then the use of the same meter black ground lead to pin 5 and the red AC meter lead needs to sample both the pin 15 and 6 tmusic tone inputs of that IC after you have powered up and had mamacita press a key for you.
I might expect an incoming tone level to be on down in the two tenths of a volt level . . .or possibly even weaker / lower . until the key is released.
(Pray for an indication / presence ! )
S o o o o . . .if having our chips full power supply level being present, and your actually measuring a generated musical tone coming over to the inputs, and you then measuring its presnce, is leaning towards the LA4127 being suspect.

73's de Edd . . . . .

Hello Sir, I repeated the test of LA4127 , this time with battery power only.

PIN 11 vs PIN 1 : 1.05 Vdc
PIN 11 vs PIN 5 : 1.05 Vdc
PIN 11 vs PIN 10 : 1.05 Vdc

 

[LJ89]

These measurements indicate that power supply is bad. Pin 7 is the power supply input to the regulator and should not be at 0 V. Provided your measurements are correct.

When you say power supply do you mean the wall wart has gone bad?

 

[Harald Kapp]

No, I think somethingin the circuit pn board the Casio in the power supply section. Hard to say where to look without a schematic (I couldn't find one) or physical access to the board.

 

[LJ89]

No, I think somethingin the circuit pn board the Casio in the power supply section. Hard to say where to look without a schematic (I couldn't find one) or physical access to the board.

Is there any other tests I can do to help locate the problem .. like test resistors or capacitors?

 

[73's de Edd]

Sir LJ89 . . . .

You tell Sir Harald . . . . when you are dealing with the CA5668 I.C. . . .that . . .
I re tested pin 7 vs pin 4 : 0 V
and pin 7 vs pin 9 : 0.1 mV
I see that as being correct. ###
but when I test pin 7 against pin 1, or pin 2, they read 9 Vdc.
I also agree with those voltage readings ###
This might seem like a dumb question but If I use a jumper wire and give pin #7, 9 Vdc could that be a way I can test the chip?
In my circuit tracing and then fully analyzing that, I would be more concerned with the impending ALARMING effect to ensue *****

In Harald saying that pin 7 of the CA5668 is its power input, and if I am using the most common San -YO O O O O data sheet.
And that is being sourced from an internet sourcing, that copy is being / having one spotty quality of reproduction . . . . and therein, I might just interpret a blurred pin 1 as a 7.
To correct for that, let me just graphically whip us up a better version of that to work with . . . . . . and even a relevant block diagram.

VOILA ! . . . . . . . . ( and that's being REAL heav-ee on its voil aspect. )




Here I also have it used in an application at the bottom.
The chip has its ground and each of the two inner contained regulator circuts have their grounds.
The real time application at the bottom has all grounds combined so have done the same up at the top.
PLUS your unit is the same way.
When Harald had you measuring voltages , you were measuring between common shared grounds ! ###
But when you measured between pins 1 and 3 to 7 you found normal expected supply voltage, look above and you will see that.

WHAT IS TO BE EXPECTED . . . .
There is being need for the 3 . . . . . VC VA and VD . . . . . supplies to be activated for the unit to power on and be able to work.
Your 9VDC VDIN on pin 3 comes directly in and is regulated down to 5VDC to then pass out pin 8 as your 5 VDC digital supply line.
(Extra filtering and bypassing isolation is used for feeding digital supply lines )
This then has the system (uP) powered up in standby and waiting to see if you ever push the units power switch. If so, a logic high
signal / voltage passes down to the pin 10 Auto Power On/off .
That pin 10 signal activates the VA supply with a 5'ish volt output at pin 6 as the VA supply.
(That supply is adjustable with selectively chosen pairs of resistors used as a voltage divider bridge feeding to pin 5.)
As soon as it activates, also see the arrow path up to the control of that SOLID STATE SWITCH between pin 1 and 3 and that then lets the full 9V thru to feed your LA4127 power audio amp and two ancillary bipolar, tone filtering / digital cleanup transistors.
FIO . . . . VA also feeds a turn on arrow path down to VD regulator BUT they chose to power it as always on via the direct connection of pin 3 to main power.

A TEST SEQUENCE . . . .
Battery up and see if you are getting battery power to Pin 1 and 3 as +9V in.
Ground can be 4-7 or 9.
Move meter + to pin 8 and expect +5'ish voltage
Monitor pin 10 to see what votage is initially there. Turn on the units power switch and see if up to 5 VDC shows up at 10.
If all is well, expect 5'ish volts at pin 6 of the VA supply.
THEN see if there is now being pass thru of 9VDC voltage at pin 2 with being switched thru from pin 1 . . . . . the 9 VDC source.

Explanation for the above *****
If you place your 9 volts at its potential 50 watt current capability between two ground connections that Harald initially gave you, which are ACTUALLY being inter joined by a thin foil trace , expect heat, delamination, 'tinky, and heat up . . . . potentially to the burn open / vaporization stage of the foil.

OBSERVATION . . .
On your findig your common metering ground.
All of our testing can have you using one ground plane.
Look about the PCB and note at least 4 points / holes where it seems that they have been playing with board etching and tinning of the exposed etch with the result of mini solder blobs looking like that they had then created a star lock washer profile with micro solder pads.
That is to assure good grounding to frame, with those solder connections pressing into it.
Also you see that they are all within and connected to a foil surround that completely encircles the PCB.
Stab your BLACK meter wire into solder blobs anywhere on that ground plane.

Then you tell me . . . . . when you are NOW dealing with the different LA4127 I.C. . . .that . . .
PIN 11 vs PIN 1 : 1.05 Vdc
PIN 11 vs PIN 5 : 1.05 Vdc
PIN 11 vs PIN 10 : 1.05 Vdc

Which tells me that I now need go thru prepping an additional test procedure for your then finding out why that is ?

Thaaaaaaaassit . . . fer now.


73's de Edd . . . . .


As a baby, I was so absolutely ugly, that my mother started having morning sickness AFTER I was born.

 

[LJ89]

Sir LJ89 . . . .

You tell Sir Harald . . . . when you are dealing with the CA5668 I.C. . . .that . . .
I re tested pin 7 vs pin 4 : 0 V
and pin 7 vs pin 9 : 0.1 mV
I see that as being correct. ###
but when I test pin 7 against pin 1, or pin 2, they read 9 Vdc.
I also agree with those voltage readings ###
This might seem like a dumb question but If I use a jumper wire and give pin #7, 9 Vdc could that be a way I can test the chip?
In my circuit tracing and then fully analyzing that, I would be more concerned with the impending ALARMING effect to ensue *****

In Harald saying that pin 7 of the CA5668 is its power input, and if I am using the most common San -YO O O O O data sheet.
And that is being sourced from an internet sourcing, that copy is being / having one spotty quality of reproduction . . . . and therein, I might just interpret a blurred pin 1 as a 7.
To correct for that, let me just graphically whip us up a better version of that to work with . . . . . . and even a relevant block diagram.

VOILA ! . . . . . . . . ( and that's being REAL heav-ee on its voil aspect. )

View attachment 50805


Here I also have it used in an application at the bottom.
The chip has its ground and each of the two inner contained regulator circuts have their grounds.
The real time application at the bottom has all grounds combined so have done the same up at the top.
PLUS your unit is the same way.
When Harald had you measuring voltages , you were measuring between common shared grounds ! ###
But when you measured between pins 1 and 3 to 7 you found normal expected supply voltage, look above and you will see that.

WHAT IS TO BE EXPECTED . . . .
There is being need for the 3 . . . . . VC VA and VD . . . . . supplies to be activated for the unit to power on and be able to work.
Your 9VDC VDIN on pin 3 comes directly in and is regulated down to 5VDC to then pass out pin 8 as your 5 VDC digital supply line.
(Extra filtering and bypassing isolation is used for feeding digital supply lines )
This then has the system (uP) powered up in standby and waiting to see if you ever push the units power switch. If so, a logic high
signal / voltage passes down to the pin 10 Auto Power On/off .
That pin 10 signal activates the VA supply with a 5'ish volt output at pin 6 as the VA supply.
(That supply is adjustable with selectively chosen pairs of resistors used as a voltage divider bridge feeding to pin 5.)
As soon as it activates, also see the arrow path up to the control of that SOLID STATE SWITCH between pin 1 and 3 and that then lets the full 9V thru to feed your LA4127 power audio amp and two ancillary bipolar, tone filtering / digital cleanup transistors.
FIO . . . . VA also feeds a turn on arrow path down to VD regulator BUT they chose to power it as always on via the direct connection of pin 3 to main power.

A TEST SEQUENCE . . . .
Battery up and see if you are getting battery power to Pin 1 and 3 as +9V in.
Ground can be 4-7 or 9.
Move meter + to pin 8 and expect +5'ish voltage
Monitor pin 10 to see what votage is initially there. Turn on the units power switch and see if up to 5 VDC shows up at 10.
If all is well, expect 5'ish volts at pin 6 of the VA supply.
THEN see if there is now being pass thru of 9VDC voltage at pin 2 with being switched thru from pin 1 . . . . . the 9 VDC source.

Explanation for the above *****
If you place your 9 volts at its potential 50 watt current capability between two ground connections that Harald initially gave you, which are ACTUALLY being inter joined by a thin foil trace , expect heat, delamination, 'tinky, and heat up . . . . potentially to the burn open / vaporization stage of the foil.

OBSERVATION . . .
On your findig your common metering ground.
All of our testing can have you using one ground plane.
Look about the PCB and note at least 4 points / holes where it seems that they have been playing with board etching and tinning of the exposed etch with the result of mini solder blobs looking like that they had then created a star lock washer profile with micro solder pads.
That is to assure good grounding to frame, with those solder connections pressing into it.
Also you see that they are all within and connected to a foil surround that completely encircles the PCB.
Stab your BLACK meter wire into solder blobs anywhere on that ground plane.

Then you tell me . . . . . when you are NOW dealing with the different LA4127 I.C. . . .that . . .
PIN 11 vs PIN 1 : 1.05 Vdc
PIN 11 vs PIN 5 : 1.05 Vdc
PIN 11 vs PIN 10 : 1.05 Vdc

Which tells me that I now need go thru prepping an additional test procedure for your then finding out why that is ?

Thaaaaaaaassit . . . fer now.


73's de Edd . . . . .


As a baby, I was so absolutely ugly, that my mother started having morning sickness AFTER I was born.

Hello Sir,

I had to re read your instructions a few times making sure I understood everything! (I'm hoping I understood properly)

Here are my readings.

CA5668:

Battery powered ( NOT PLUGGED INTO WALL) device switched to ON position (red light on)

PIN 1 vs 4 : 9.05v
PIN 1 vs 5 : 8.75v
PIN 1 vs 6 : 7.76v
PIN 1 vs 7 : 9.05v
PIN 1 vs 9 : 9.05v

PIN 3 vs 4 : 9.05v
PIN 3 vs 5 : 8.74v
PIN 3 vs 6 : 7.76v
PIN 3 vs 7 : 9.05v
PIN 3 vs 9 : 9.05v


I re did the test, still battery powered only, this time with the on/off switch in the OFF position ( no red light glowing)

PIN 1 vs 4 : 9.28v
PIN 1 vs 5 : 9.25v
PIN 1 vs 6 : 9.27v
PIN 1 vs 7 : 9.23v
PIN 1 vs 9 : 9.28v

PIN 3 vs 4 : 9.29v
PIN 3 vs 5 : 9.29v
PIN 3 vs 6 : 9.29v
PIN 3 vs 7 : 9.29v
PIN 3 vs 9 : 9.29v


BATTERY POWERED ONLY, SWITCHED OFF
PIN 4 vs 8 : 5.04v


BATTERY POWERED ONLY, SWITCHED ON
PIN 4 vs 8 : 5.02v



SWITCHED OFF
PIN 10 vs 4 : 2mV


SWITCHED ON
PIN 10 vs 4 : 4.95v



NOW the testing of LA4127 (after stabbing the star lock washer looking solder blobs)

SWITCHED ON, BATTERIES ONLY
PIN 11 vs PIN 1 : 8.35 Vdc
PIN 11 vs PIN 5 : 8.35 Vdc
PIN 11 vs PIN 10 : 8.35 Vdc

SWITCHED OFF
PIN 11 vs PIN 1 : 1.13 Vdc
PIN 11 vs PIN 5 : 1.13 Vdc
PIN 11 vs PIN 10 : 1.13 Vdc

Let me know if I can do anything else! Thanks again!


also ive attached this picture, are these what you were referring too?

 

[Harald Kapp]

Pin 7 is the power supply input to the regulator

I'm sorry, that's dumb. My bad. Should have read pin 1.

 

[LJ89]

I'm sorry, that's dumb. My bad. Should have read pin 1.

Seeing as pin 1 is power supply, what does that change for the keyboard ? Is it likely the problem is still in the power supply section of the circuit board?

 

[kenny256]

I'm sorry, that's dumb. My bad. Should have read pin 1.

Maybe should edit or delete post #8 and 25 to remove incorrect information?

 

[LJ89]

Anyone have an idea what else I could do ? I'm really stuck here... and would really like to fix this keyboard. Thank you all !

 

[73's de Edd]

Sir LJ89 . . . . .

Why 'soitanly, since your previous testing is revealing that the two regulators are regulating their inputted 9VDC of SOLID battery power, properly, on down to ~ 5VDC .
Also a portion of the uP's digital aspect is recognizing and responding, to appropriately turn on the Va supply, coming out of pin 6.

NOW, we just need to know the voltage output out of pin 5668 pin 2, both switched off and then being turned on.

The question now is ?

SWITCHED OFF SWITCHED ON
PIN 1's voltage? vs pin 2 :? V PIN 1's voltage vs pin 2 : ? V
(Using meter black lead to ground on both tests .)

Hopefully it will be in the 9VDC range, BUT from your prior test over at the 4127, then, it was only being 1.8 VDC at pin 11 from pins 1-5-10 (all are being the SAME), and I would still suspect the same reading . . . . . going over to pin 11 ( the important one).
That thereby suggests of a fault within the internal solid state switch of the 5668 IC (unlikely) , or within the internals of the 4127, which has crunched down to a 15 ohm or so, "load" / SHORT.

If you still do find that situation, pull out the batteries cells and get the Klein out and put in low ohms range and measure to see what resistance is being measured between those same pins of the 4127 again.
If you find that low resistance IS being the situation, and your having the equipment and proper techno / mechanico prowess to then properly / non destructively ? ? ? ? ? desolder just that pin 11 so that it then floats free from being connected .
Tell me accordingly .

Previously . . . .


TESTED
BEING BATTERY POWERED ONLY

SWITCHED OFF SWITCHED ON
PIN 4 vs 8 : 5.04v PIN 4 vs 8 : 5.02v

That is correct as 9VDC is coming into the VD regulator section and it is then regulating down and passing 5 VDC to the pin 8 as the V Digital supply . . . . it is operating with the main power switch being either on or off ( due to a miniscule power demand in uPsleep mode)

SWITCHED OFF SWITCHED ON
PIN 10 vs 4 : 2mV PIN 10 vs 4 : 4.95v
This is your command line from uP output to this regulator chip and your readings confirm correctness of action.

F.I.O. . . .uP = microprocessor . . . ( comm-pewter on a cowchip )

Thaaaaaaaaaasssssssit . . . . .

73's de Edd . . . . .


Ever notice the " oxymoron" of how all of our clothing irons have that setting for:
" PERMANENT " press? . . . . . now, I just don't get it ?



.

 

[LJ89]

Sir LJ89 . . . . .

Why 'soitanly, since your previous testing is revealing that the two regulators are regulating their inputted 9VDC of SOLID battery power, properly, on down to ~ 5VDC .
Also a portion of the uP's digital aspect is recognizing and responding, to appropriately turn on the Va supply, coming out of pin 6.

NOW, we just need to know the voltage output out of pin 5668 pin 2, both switched off and then being turned on.

The question now is ?

SWITCHED OFF SWITCHED ON
PIN 1's voltage? vs pin 2 :? V PIN 1's voltage vs pin 2 : ? V
(Using meter black lead to ground on both tests .)

Hopefully it will be in the 9VDC range, BUT from your prior test over at the 4127, then, it was only being 1.8 VDC at pin 11 from pins 1-5-10 (all are being the SAME), and I would still suspect the same reading . . . . . going over to pin 11 ( the important one).
That thereby suggests of a fault within the internal solid state switch of the 5668 IC (unlikely) , or within the internals of the 4127, which has crunched down to a 15 ohm or so, "load" / SHORT.

If you still do find that situation, pull out the batteries cells and get the Klein out and put in low ohms range and measure to see what resistance is being measured between those same pins of the 4127 again.
If you find that low resistance IS being the situation, and your having the equipment and proper techno / mechanico prowess to then properly / non destructively ? ? ? ? ? desolder just that pin 11 so that it then floats free from being connected .
Tell me accordingly .

Previously . . . .


TESTED
BEING BATTERY POWERED ONLY

SWITCHED OFF SWITCHED ON
PIN 4 vs 8 : 5.04v PIN 4 vs 8 : 5.02v

That is correct as 9VDC is coming into the VD regulator section and it is then regulating down and passing 5 VDC to the pin 8 as the V Digital supply . . . . it is operating with the main power switch being either on or off ( due to a miniscule power demand in uPsleep mode)

SWITCHED OFF SWITCHED ON
PIN 10 vs 4 : 2mV PIN 10 vs 4 : 4.95v
This is your command line from uP output to this regulator chip and your readings confirm correctness of action.

F.I.O. . . .uP = microprocessor . . . ( comm-pewter on a cowchip )

Thaaaaaaaaaasssssssit . . . . .

73's de Edd . . . . .


Ever notice the " oxymoron" of how all of our clothing irons have that setting for:
" PERMANENT " press? . . . . . now, I just don't get it ?



.

Hey Dr. Edd,

I just want to make sure I understand you perfectly clear.

When I test pin 1 and pin 2 of CA5668 do I keep the black probe on that grounding plane (yellow box with red arrows, star washing looking solder blobs)

If that's the case these are my results.

BATTERY POWERED ON:

PIN 1 : 9.04V
PIN 2 : 8.36V

BATTERY POWERED OFF:

PIN 1 : 9.25V
PIN 2 : 1.1V (and slowly decreasing if I keep the multimeter probe on it, It went down from 1.4V to 1.1V over a minute or so... I feel like it would have went down more but I didn't keep the multimeter probe on it..)




Also I feel like I did not do the 4127 test properly when you asked me this:

OBSERVATION . . .
On your findig your common metering ground.
All of our testing can have you using one ground plane.
Look about the PCB and note at least 4 points / holes where it seems that they have been playing with board etching and tinning of the exposed etch with the result of mini solder blobs looking like that they had then created a star lock washer profile with micro solder pads.
That is to assure good grounding to frame, with those solder connections pressing into it.
Also you see that they are all within and connected to a foil surround that completely encircles the PCB.
Stab your BLACK meter wire into solder blobs anywhere on that ground plane.

Then you tell me . . . . . when you are NOW dealing with the different LA4127 I.C. . . .that . . .
PIN 11 vs PIN 1 : 1.05 Vdc
PIN 11 vs PIN 5 : 1.05 Vdc
PIN 11 vs PIN 10 : 1.05 Vdc




I didn't keep my BLACK probe on the grounding plane, I only poked it momentarily and than returned to to PIN 11 while placing my red PROBE on pin 1, pin 5 and pin 10.

I HAVE RE done the test of 4127... THIS TIME I KEPT MY BLACK PROBE on the grounding plane (star washer solder blobs) the whole time.... AND ONLY MOVED THE RED PROBE.

THESE are my results...

BATTERY POWERED OFF

Black probe on grounding plane, Red probe on PIN 11 : 1.24V

Black probe on grounding plane, Red probe on PIN 10 : 0V

Black probe on grounding plane, Red probe on PIN 5 : 0V

Black probe on grounding plane, Red probe on PIN 1 : 0V


BATTERY POWERED ON

Black probe on grounding plane, Red probe on PIN 11 : 8.4V

Black probe on grounding plane, Red probe on PIN 10 : 0.4mV

Black probe on grounding plane, Red probe on PIN 5 : 0V

Black probe on grounding plane, Red probe on PIN 1 : 0V

Is this how you wanted me to perform the testing?



I did the resistance test on 4127... these are my results.. I wasn't sure if I needed to test resistance between PIN 11 and PIN 1,5,10 or BETWEEN the GROUNDING PLANE and PINS 1,5,10, and 11.. so I did both and here are the results...


RED LEAD ON PIN 11, BLACK LEAD ON PIN 1 : 2.8 MOHMS (MEGA OHMS)

RED LEAD ON PIN 11, BLACK LEAD ON PIN 5 : 2.8 MOHMS (MEGA OHMS)

RED LEAD ON PIN 11, BLACK LEAD ON PIN 10 : 2.8 MOHMS (MEGA OHMS)



RED LEAD ON PIN 11, BLACK LEAD ON GROUNDING PLANE : 2.2 MOHMS (AND SLOWLY CLIMBING)

RED LEAD ON PIN 1, BLACK LEAD ON GROUNDING PLANE : 0.1 ohms

RED LEAD ON PIN 5, BLACK LEAD ON GROUNDING PLANE : 0.1 ohms

RED LEAD ON PIN 10, BLACK LEAD ON GROUNDING PLANE : 0.1 ohms

Let me know is this is what you needed and if I did the test properly...

Also should I go ahead and desolder PIN 11 of 4127? and if so.. what should I look for after I desolder PIN 11..

Thank you Dr. Edd

 

[73's de Edd]

Also should I go ahead and desolder PIN 11 of 4127? and if so.. what should I look for after I desolder PIN 11..

NO . . . . no need to float / desolder pin 11 that was being related to your initially only finding 1.8 VDC on it.
Your retest has now shown that the 4117 is NOT severely loading down your input power. . .and is actualluy pulling ~
~ 300 mw.

BATTERY POWERED ON:

PIN 1 : 9.04V
PIN 2 : 8.36V

BATTERY POWERED OFF:

PIN 1 : 9.25V

Can you now do my earlier test of going into AC metering mode in 1 VAC or less range and measure with meter neg to ground and red meter lead to
4127 and replicate the earlier procedure found in post # 24. Repetitively key in and then stop a note and the meter should respond accordingly.
Therewith, we are wanting to know if there actually is a note being created back at the uPs output and then showing up at the audio input of the 4127.
If being so, we will then have to further evaluate the units 4127 situation.